SKU for classic (all green): 040-0122 SKU for power (multi color): 040-0122-C The Block-of-1000 is great for learning to count, add, subtract, multiply, and divide. It works great on its own, but if you want to really work on connecting the physical operations to how they are written, we recommend you also get 3-Place Counter. No other blocks work like Digi-Block: Our blocks pack and unpack, meaning kids can start using the blocks without having to know that "10 blocks is 1 ten." You'll be amazed how much more intuitive math is when you don't have to trade! Our blocks are all the same shape! Only the size changes. Have you used Dienes Blocks? What do you think 10,000 looks like in Dienes Blocks? If you weren't able to figure it out, imagine what a kid learning math for the first time is thinking! How are our blocks so cool? Harvard Business School Professor Elon Kohlberg teamed up with the legendary design studio IDEO to come up with something special. Their passion? To show the beauty of math and its simplicity and to stop kids fearing math. Watch this video to see exactly what a Block-of-1000 is made of!     And watch this video to see it in action :)